Downspouts having hinge arrangements are known for attachment to the eavestrough systems of buildings. The hinge arrangements facilitate the swinging up and down of a hinged extension for passage therebelow of lawn-grooming equipment and the like.
Although, the hinged extensions conventionally have been actuated manually, some arrangements have been devised for releasing the hinged extension in response to the passage of rain water through the downspout. Some other arrangements have been devised for automatically returning the hinged extension to a storage position after the passage of rain water has stopped. For example, U.S. Pat. No. 3,375,851 to Fitzhenry et al., issued Apr. 2, 1968, discloses a downspout in which a hinged extension is lowered from a storage position into a position for use when a counterbalanced receptacle in association with the hinged extension fills with rain water. The hinged extension of this downspout is actuated to return to the storage position when the passage of water through the downspout is insufficient to overcome the force of a counterweight tending to rotate the extension upwards. This downspout requires a steady, heavy flow of water through the extension to maintain it in its lowered position. In weather conditions where the precipitation is light or intermittent the extension swings up and down. This has been found to inhibit customer acceptance and to cause failure of the hinge attachment. An automatic downspout extension is needed which is effective during light and intermittent rainfall as well as during heavy rainfall.